Fiber mix for yarn and fabrics

ABSTRACT

A yarn comprises a blend of two or more types of fibers. Fibers of viscose incorporating silica compose 50-85% by weight of the yarn. Fibers of modacrylic compose 15-50% by weight of the yarn. A composite yarn with a core being defined by the yarn is also provided. The composite yarn has a sheath surrounding the core.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the priority of U.S. Patent Application No. 62/597,661, filed on Dec. 12, 2017, and incorporated herein by reference.

FIELD OF THE APPLICATION

The present application relates to yarns used in textiles and fabrics having flame-resistant properties.

BACKGROUND OF THE ART

Textiles have evolved drastically for uses in various applications, in which the technical features of the textile perform different protective functions. For instance, textiles may be flame-resistant, may protect against electric arc, may be waterproof yet breathable, may be puncture proof or rip proof, among numerous other possible characteristics. Oftentimes, the textiles gain their characteristics from the yarns or fibers that constitute them.

The challenge remains to offer textiles with such protective features, while preserving other characteristics. For example, garments made with textiles having such protective features must remain as lightweight and flexible as possible and thus not hamper free movements of the wearer. Moreover, it is desired that fabrics made of protective yarns emulate as much as possible other known types of fabrics, such as denim. Other characteristics apply to other applications as well. On the other hand, the cost must also be factored in as an important design factor in the choice of a yarn for protective textile.

SUMMARY OF THE APPLICATION

It is therefore an aim of the present invention to provide novel fiber mix for yarn.

Therefore, in accordance with a first embodiment of the present application, there is provided a yarn comprising: a blend of at least two types of fibers, including at least fibers of viscose incorporating silica composing 50-85% by weight of the yarn, and fibers of modacrylic composing 15-50% by weight of the yarn.

Further in accordance with the first embodiment, the fibers of viscose have a linear mass density ranging between 1.5 and 3.5 deniers, inclusively.

Still further in accordance with the first embodiment, the fibers of viscose are for instance staple fibers of viscose.

Still further in accordance with the first embodiment, a substantial portion of the staple fibers are for instance between 35 mm and 120 mm in length.

Still further in accordance with the first embodiment, the fibers of modacrylic have for instance a linear mass density ranging between 1.0 and 3.0 deniers, inclusively.

Still further in accordance with the first embodiment, the fibers of modacrylic are for instance staple fibers.

Still further in accordance with the first embodiment, a substantial portion of the staple fibers of modacrylic are for instance between 35 mm and 120 mm in length.

Still further in accordance with the first embodiment, the blend of fibers has for instance a fiber-to-fiber dispersion of the fibers.

Still further in accordance with the first embodiment, fibers of meta-aramid compose for instance at most 20% by weight of the yarn.

Still further in accordance with the first embodiment, fibers of para-aramid compose for instance at most 20% by weight of the yarn.

Still further in accordance with the first embodiment, fibers of nylon compose for instance at most 20% by weight of the yarn.

Still further in accordance with the first embodiment, a yarn count is for instance between 20 tex and 250 tex, inclusively.

In accordance with a second embodiment of the present application, there is provided a composite yarn comprising: a core, the core being defined by the yarn as described above; and a sheath surrounding the core.

Further in accordance with the second embodiment, the sheath includes cellulosic fibers.

Still further in accordance with the second embodiment, the sheath includes cotton fibers, lyocell or viscose fibers.

Still further in accordance with the second embodiment, the sheath is for instance 100% cotton fibers.

Still further in accordance with the second embodiment, the cotton is for instance non-treated.

Still further in accordance with the second embodiment, the sheath includes for instance nylon fibers.

Still further in accordance with the second embodiment, the sheath has for instance fibers of corespun around the core.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table illustrating fiber mixes of a yarn according to the present disclosure; and

FIG. 2 is a schematic view of the yarn of FIG. 1 with a sheath thereon, in accordance with an embodiment of the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present application pertains to a yarn and to a fiber mix (a.k.a., fibre mix) used for a yarn in accordance with the present disclosure. Referring to FIG. 1, the fiber mix in accordance with the present disclosure comprises two or more fiber types that concurrently provide particular properties to the yarn of the present disclosure. Moreover, a textile made of the yarn has a texture and feel emulating that of denim. The yarn of the present disclosure has a blend of fibers 10 and 20. The blend may include other fibers, such as fibers 30 and/or 40 in the table of FIG. 1. According to an embodiment, the fibers 10, 20, 30 and/or 40 are staple fibers, i.e., discrete fiber segments.

Fiber 10 in FIG. 1 is present in a ratio ranging between 50% and 85% by weight of the yarn, and is viscose that incorporates silica. The incorporation of polysilicic acid into the cellulosic structure of viscose enhances the fire resistance of the hybrid fiber by distinct mechanisms, such as by the formation on the fiber surface of an inherently incombustible char of silica residue, and by a lowering of the temperature at which water is released from the fiber. The fiber 10 may be viscose FR (fire resistant). In an embodiment, the fibers 10 of viscose are staple fibers of viscose with silica. The staple fibers 10 may have a linear mass density ranging between 1.5 and 3.5 deniers, inclusively, though the linear mass density may be more or less. The staple fibers 10 may have a linear density of 1.66 to 3.89 grams per 10,000 meters, in an embodiment, but it may be outside of this range as well in other embodiments. The staple fibers 10 may have a diameter between 11.5 μm and 17.6 μm, inclusively, also with the possibility of being more or less. In the case of staple fibers, the fiber length of an individual fiber 10 of viscose is between 35 mm and up to 120 mm. Some fibers 10 may be out of this range, for example a proportion of the fibers 10 may be longer or shorter.

Fiber 20 in FIG. 1 is present in a ratio ranging between 15% and 50% by weight of the yarn. In an embodiment, fiber 20 is modacrylic (e.g., composed of less than 85% and more than 35% by weight of acrylonitrile units). In an embodiment, the fibers 20 of modacrylic are staple fibers. The staple fibers 20 may have a linear mass density ranging between 1.0 and 3.0 deniers, inclusively, though the linear mass density may be more or less. The staple fibers 10 may have a linear density of 1.10 to 3.30 grams per 10,000 meters, in an embodiment, but it may be outside of this range as well in other embodiments. The staple fibers 20 of modacrylic may have a diameter ranging inclusively between 9.5 μm and 17.0 μm, also with the possibility of being more or less. In the case of staple fibers, the fiber length of an individual fiber of modacrylic is between 35 mm and up to 120 mm. Some fibers 20 may be out of this range, for example a proportion of the fibers 20 may be longer or shorter.

According to an embodiment, the fiber mix of the yarn has only these two fibers, with the viscose with silica constituting between 50% and 85% of the weight of the yarn, and the modacrylic forming the balance of the weight. This is shown in blend A, blend B and blend I in FIG. 1, with viscose to modacrylic ratios of 85:15, 70:30, and 50:50, respectively.

The combination of these fibers 10 and 20 creates a synergy that increases the flame-resistance performance of each of these fibers, in comparison to if they were used alone. A yarn of these two fibers in the above-referred ratios, with or without additional fibers, responds well to various flame-resistance tests like Vertical flame and Flash Fire Manikin. Once submitted to an open flame, a fabric woven from the yarn as above does not burn, melt nor drip in the time delays according to the NFPA 2112 standard. The fabric integrity is well preserved in comparison to other flame-resistant fabrics, i.e., the fabric does not crack, and holes do not appear when submitted to an open flame for 3 seconds.

The fibers 10 and 20 must be well distributed inside the yarn so that the synergy of the blend works at an optimal level. The blend of modacrylic and viscose (e.g., viscore FR) is done in such a way that the dispersion of the two fibers is said to be fiber-to-fiber (a.k.a., fibre-to-fibre), at the staple fiber level. According to an embodiment, the two fibers 10 and 20 may be combined early in the manufacturing process of the textile yarns, before the spinning itself, for instance at the carding process (intimate blend) or at the drawing process (draw blend). If properly fabricated, a fabric made from the yarn may comply with the NFPA2112-2012 Standard, i.e., Standard on Flame-Resistant Garments for Protection of Industrial Personnel Against Flash Fire.

It is also possible to incorporate a third component, a fourth component, etc, in the yarn to provide additional functionality to the yarn and textile. For instance, additional functionalities include increasing the resistance to washing (abrasion resistance), increasing the strength of the fabric and/or increasing protection to fire. As shown in FIG. 1, the fibers 30/40 may not exceed 20% of the total yarn weight, while silica-containing viscose at fiber 10 is present at 50% or above by weight. In some embodiment, the fibers 30/40 may exceed 20% of the total yarn weight.

Fiber 30 in FIG. 1 may be present in a ratio ranging between 0% and 20% by weight of the yarn. The fiber 30 is meta-aramid, para-aramid or aramid-type fiber. The meta-aramid fiber (e.g., Nomex®, Conex®) may be used to increase the yarn tenacity without affecting the fire retardant property of the yarn. Alternatively, the aramid-type fiber is a para-aramid (e.g., Kevlar®, Twaron®) that increases the tensile strength of the yarn. Both the para-aramid fibers and meta-aramid fibers could be greige (dyeable) fibers or dope dyed fibers. It is also considered to use raw fiber dying, dope dying before extrusion or greige. When the fiber 30 is a dope-dyed or fiber-dyed meta-aramid, other fibers in the yarn may be dyed using atmospheric pressure without affecting the fire protection of the fabric.

The staple fibers 30 of meta-aramid and/or para-aramid may have a linear mass density ranging between 1.0 deniers and 3.0 deniers inclusively, though the linear mass density may be more or less. The staple fibers 30 of meta-aramid may have a linear density of 1.10 to 3.30 grams per 10,000 meters, but it may be outside of this range as well in other embodiments. The staple fibers 30 of meta-aramid may have a diameter ranging inclusively 10.1 μm and 17.6 μm. The fiber length of an individual fiber of meta-aramid is between 35 mm up to 120 mm.

Fiber 40 in FIG. 1 is present in a ratio ranging between 0% and 20% by weight of the yarn, and is nylon. Nylon may be used to increase the yarn tenacity, resistance to abrasion, without affecting the fire retardant property of the yarn. Although not shown in FIG. 1, the yarn may have both fiber 30 and fiber 40 in a combined total weight in a ratio ranging between 0% and 20% by weight of the yarn. In another embodiment, the fourth component is an anti-static fiber.

In an embodiment, the fibers 40 of nylon are also staple fibers. The staple fibers 40 may have a linear mass density ranging between 0.9 and 3.25 deniers, inclusively, though the linear mass density may be more or less. The staple fibers 40 may have a linear density of 1.0 to 3.3 grams per 10,000 meters, in an embodiment, but it may be outside of this range as well in other embodiments. The staple fibers 40 of nylon may have a diameter ranging inclusively between 10.6 μm and 20.1 μm, also with the possibility of being more or less. In the case of staple fibers, the fiber length of an individual fiber 40 of nylon is between 35 mm and up to 120 mm. Some fibers 40 may be out of this range, for example a proportion of the fibers 40 may be longer or shorter.

The addition of the fibers 30 and/or 40 to the fibers 10 and 20 may also be done at the staple fiber level using intimate blending for a fibre-to-fibre combination of the staple fibers.

The yarn may be woven or knitted into various fabrics. In a non-limitative embodiment, the yarn has a twill weaving to emulate a denim fabric. In particularly, the weft is weaved to pass under two or more warp threads to resemble denim. Accordingly, with appropriately dyed yarn and appropriate twill weaving, a textile made of the yarn as above may be similar to a denim in feel and look, while procuring effective protection against flash fire and flame to the wearer. Moreover, a fabric made using the yarn provides suitable protection against heat transfer and against electrical arcs.

Textiles made with the yarn may be used as part of textiles and fabrics, for any appropriate application, including non-exhaustively clothing, protective garment, accessories, upholstery, furniture material (e.g., plane seat covers) to name but a few.

The yarn count for the yarn of FIG. 1 constituted as described above may be between 20 tex and 250 tex. A textile made of the yarn 10 may have the properties described above when woven with a surface weight ranging between 4.5 and 25.0 ounces per square yards.

There may be numerous applications for textiles featuring the yarn. As a non-exhaustive, exemplary list, the yarn 10 may be used as part of woven coveralls for the oil and gas industry (NFPA 2112 compliant), construction garment (woven), electrician pants (woven), fireproof partition (woven), military and workers fire-resistant underwear (knitted), fire-resistant socks for military and workers (knit), textile fireproof barrier for foam mattress (knitted or woven).

It is contemplated to use the yarn of FIG. 1 in a sheath surrounding a core. For example, referring to FIG. 2, another embodiment of the present disclosure is shown, in which the yarn with blends according to FIG. 1 is used as a core 51 of a composite yarn 50. In the composite yarn 50, a sheath 52 surround the core 51. The sheath 52 may be made of any material. According to an embodiment, if the textile made from the composite yarn 50 is to emulate denim, the sheath 52 is cotton, such as 100% cotton. For example, the cotton of the sheath 52 may be traditional non-treated cotton fibers. Other cellulosic fibers may be used, including viscose, to form the sheath 52. All such fibers may be staple fibers. It is contemplated to blend in other fibers as well, to make up the sheath 52. For example, there may be between 0-20% of another fiber in a blend of the yarn of the sheath 52, such as nylon.

It is contemplated to add the sheath 52 onto the core 51 by way of a corespun technique, using cotton fibers. Consequently, the composite yarn 50 has a core 51 with one or more yarns or fibers twisted around the core 51. More specifically, the yarn as in FIG. 1 is spun, and is made of a blend the viscose fibers 10/modacrylic fibers 20 with or without meta-aramid and/or para-aramid fibers 30 and/or nylon fibers 40. Once the blended yarn is spun, for example as a first step, this blended yarn may be used as a core 51 to be introduce in a core spinning process as a second step to spin around this initial yarn 51 a sheath 52 of cellulosic fiber (as cotton, lyocell, or viscose). This process is done in such a way to have the sheath 52 of cellulosic fibers at the surface of the yarn/core 51, whereby the dyeing of the exterior of cellulosic fiber may be achieved in any color that would be required. It is understood that the ratio sheath 52/core yarn 51 would be more than 1.0. In other words, the linear weight of the sheath should be 50% and more, with the sheath 52 covering up completely the core yarn 51.

According to an embodiment, the sheath 52 made of cellulosic fiber may participate in a chemical reaction under flame with the modacrylic and Viscose FR degradation, so as to inhibit the fire reaction and stop the flame from spreading into a fabric made of the composite yarn 50.

For example, one embodiment of the composite yarn 50 would be a yarn as in FIG. 1 made of 60% viscose FR staple fibers 10; 30% modacrylic staple fibers 20; 10% meta-aramid staple fibers 30 in a linear weight of 32.8 tex. Once yarn to serve as the core 51 is spun using any spinning technology (either air jet spun with intermingling, vortex spun, open-end spun, ring spun or friction spun, or Worsted spun), it is fed to a core spinning machine to become the core 51 of a yarn where a sheath of cotton is spun around it.

Again, by way of example, by adding 40.7 grams/1000 meters of cotton fibers to the surface of the yarn in the core 51, the composite yarn 50 is created, with for example a blend ratio of 55.4% cotton (outer sheath 52), 26.7% viscose FR, 13.4% modacrylic and 4.5% meta-aramid in the core 51. These proportions can each vary. The composite yarn 50 may have a linear weight of 73.8 tex±10%.

The blended yarn without the cellulosic sheath 52, as in FIG. 1 (i.e., the core 51 alone), may have a linear weight ranging between 20 tex and 255 tex. It is understood that this type of yarn could be produce and use as single yarn, like 20.0 tex (30/1Ne) or by twisting many ends of a single yarn together, such as in 85X3tex (6.9/3Ne). The construction of the yarn (single or multiple ply) would be as a function of the fabric strength required and/or fabric construction desired by the knitter or weaver.

The composite yarn 50 may have a higher linear weight because of the addition of the sheath 52. Thus, the linear weight of a yarn 51 with a cellulosic sheath 52 would be between 40 tex and 400 tex, inclusively. The composite yarn 50 could be produced and used as single core spun yarn, e.g., 40.0 tex (14.8/1Ne) or by twisting many ends of a single yarn together like 196.8X2tex (3/2Ne). The construction of the yarn (single or multiple ply) may be determined as a function of the fabric strength required and/or fabric construction desired by the knitter or weaver. 

1. A yarn comprising: a blend of at least two types of fibers, including at least fibers of viscose incorporating silica composing 50-85% by weight of the yarn, and fibers of modacrylic composing 15-50% by weight of the yarn.
 2. The yarn according to claim 1, wherein the fibers of viscose have a linear mass density ranging between 1.5 and 3.5 deniers, inclusively.
 3. The yarn according to claim 1, wherein the fibers of viscose are staple fibers of viscose.
 4. The yarn according to claim 3, wherein a substantial portion of the staple fibers are between 35 mm and 120 mm in length.
 5. The yarn according to claim 1, wherein the fibers of modacrylic have a linear mass density ranging between 1.0 and 3.0 deniers, inclusively.
 6. The yarn according to claim 1, wherein the fibers of modacrylic are staple fibers.
 7. The yarn according to claim 6, wherein a substantial portion of the staple fibers of modacrylic are between 35 mm and 120 mm in length.
 8. The yarn according to claim 1, wherein the blend of fibers has a fiber-to-fiber dispersion of the fibers.
 9. The yarn according to claim 1, further including fibers of meta-aramid composing at most 20% by weight of the yarn.
 10. The yarn according to claim 1, further including fibers of para-aramid composing at most 20% by weight of the yarn.
 11. The yarn according to claim 1, further including fibers of nylon composing at most 20% by weight of the yarn
 12. The yarn according to claim 1, wherein a yarn count is between 20 tex and 250 tex, inclusively.
 13. A composite yarn comprising: a core, the core being defined by the yarn according to claim 1; and a sheath surrounding the core.
 14. The composite yarn according to claim 13, wherein the sheath includes cellulosic fibers.
 15. The composite yarn according to claim 14, wherein the cellulosic fibers are cotton fibers, lyocell, or viscose fibers.
 16. The composite yarn according to claim 14, wherein the sheath is 100% cotton fibers.
 17. The composite yarn according to claim 15, wherein the cotton is non-treated.
 18. The composite yarn according to claim 14, wherein the sheath includes nylon fibers.
 19. The composite yarn according to claim 13, wherein the sheath has fibers of corespun around the core. 